42543755221 has 4 divisors (see below), whose sum is σ = 46411369344. Its totient is φ = 38676141100.

The previous prime is 42543755203. The next prime is 42543755227. The reversal of 42543755221 is 12255734524.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-42543755221 is a prime.

It is a super-2 number, since 2×42543755221² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (42543755227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1933807045 + ... + 1933807066.

It is an arithmetic number, because the mean of its divisors is an integer number (11602842336).

Almost surely, 2^42543755221 is an apocalyptic number.

It is an amenable number.

42543755221 is a deficient number, since it is larger than the sum of its proper divisors (3867614123).

42543755221 is a wasteful number, since it uses less digits than its factorization.

42543755221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3867614122.

The product of its digits is 336000, while the sum is 40.

The spelling of 42543755221 in words is "forty-two billion, five hundred forty-three million, seven hundred fifty-five thousand, two hundred twenty-one".